Own two drillmaster 18 volt drills with three batteries and two chargers. Anyway, two of the batteries will no longer take a charge or even light up the pilot light on the charger. I know these are cheap units, but, at $9 per battery ($29 for my Makita 9 volt) they deliver great value and much better torque.
Anyway, to my surprise, the batteries can actually be dis-assembled as opposed to cut apart with a hacksaw!! Great going HF!!! I have re-celled well over a hundred battery packs (surveying equipment, mainly) and this is the first time I didn't have to hacksaw one apart and re-assemble with tape!!
Opened up the batteries (4 Phillips screws) and observed all the corrosion. My wife reminded me of all the times I had left them in the rain. (Northwest, surprise rains all the time). Replaced the rusted out broken link, and good to go. I suppose I should have made a couple of drain holes in the battery case to obviate future corrosion should they ever be left out.
That was my Saturday morning, Ivan Vegvary